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Over the past three decades software engineering researchers have produced a wide range of techniques and tools for understanding the architectures of large, complex systems. However, these have tended to be one-off research projects, and their idiosyncratic natures have hampered research collaboration, extension and combination of the tools, and technology transfer. The area of software architecture is rich with disjoint research and development infrastructures, and datasets that are either proprietary or captured in proprietary formats. This paper describes a concerted effort to reverse these trends. We have designed and implemented a flexible and extensible infrastructure (SAIN) with the goal of sharing, replicating, and advancing software architecture research. We have demonstrated that SAIN is capable of incorporating the constituent tools extracted from three independently developed, large, long-lived software architecture research environments. We discuss SAIN’s ambitious goals, the challenges we have faced in achieving those goals, the key decisions made in SAIN’s design and implementation, the lessons learned from our experience to date, and our ongoing and future work. 

Protein ubiquitination regulates protein stability, cellular localization, and enzyme activity. Deubiquitinases catalyze the removal of ubiquitin from target proteins and reverse ubiquitination. USP13, a deubiquitinase, has been shown to regulate a variety of cellular responses including inflammation; however, the molecular regulation of USP13 has not been demonstrated. In this study, we revealed that USP13 is degraded in response to lipopolysaccharide (LPS) in Kupffer cells. USP13 levels are significantly decreased in inflamed organs, including liver tissues from septic mice. LPS reduces USP13 protein stability, not transcription, in Kupffer cells. Furthermore, LPS increases USP13 polyubiquitination. Inhibition of proteasome, but not lysosome or immunoproteasome, attenuates LPS‐induced USP13 degradation, suggesting USP13 degradation is mediated by the ubiquitin‐proteasome system. A catalytically inactive form of USP13 exhibits similar degree of degradation compared with USP13 wild‐type, suggesting that USP13 degradation is not dependent on its activity. Furthermore, USP13 degradation is dependent on new protein synthesis. Inhibition of c‐Jun N‐terminal kinase (JNK) attenuates USP13 degradation, indicating that JNK‐dependent new protein synthesis is necessary for USP13 degradation. This study reveals a molecular mechanism of regulation of USP13 degradation in Kupffer cells in response to bacterial endotoxin.